Erysiphe 211 



viollis (319), Hordcum jubatuin (6), H. murinum (272) H scca- 



H. 



ifi 



Panicum sauguinalc {66), Phleum pmtcnse -{ia^^), Poa annua, P. 

 Buck'cyana, P. bullwsa, P. ncmoralis, P. pmtcnsis, P. scrotina, P. 

 sinaica (233), P. tcmdfolia, P. trivialis, Sacchanun officinannn 

 (143), Sccalc cenalc (22) (69) (399), Scslcria cacndca (107), Trl- 

 ticmn sativum, T. Spclta, T. vulgare. 



Distribution.— Y.v\KQVY.: Britain, France, Spanisli Peninsula 

 (101), Belgium, Switzerland (176), Italy, Germany, Austria-Hun- 

 gary, Denmark, Norway, Sweden, Finland, Russia. 



Africa : Algeria. 



Asia: Cyprus, Transcaucasia (338), Persia {211), Turkestan 

 (Seravschan) (206), Siberia (235) (348), Japan. 



Australia : Thistle Island, Victoria and New South Wales 

 (225). 



North America : United States— Massachusetts. New York, 

 Pennsylvania, West Virginia (249), South Carolina (35), Michigan', 

 Illinois, Mississippi (361), Iowa (165), South Dakota, Kansas, 

 Montana, Idaho, Wyoming. Colorado, Nevada {i^i), California, 

 Washington ; Canada— Newfoundland, Ontario. 



A very distinct species in the large size of the perithecium, and 

 the large, usually numerous, asci. In these characters it some- 

 what recalls E. taurica, which differs, however, in the constantly 

 bisporous asci. In E. graminis the asci usually show no trace of 

 spores, being filled merely with granular protoplasm. When the 

 spores are produced they are eight in number; according to 

 Wolff, however, sometimes the number is only four. In Europe, 

 E. graminis, as a general rule, is characterized by this absence of 

 ascospores on the living host plant, and in the numerous material 

 examined only two cases have occurred in which any signs of 

 their production were observable. Among the twenty four ex- 

 amples of E. graminis in European exsiccati, mentioned above 



only one (Rab. Fung. Eur. no. 671) showed spores in the ascus 

 This specimen was gathered on Triticum sativum in x-\ugust ; two 

 of the asci, each containing 8 spores, are represented at Fig. 159. 

 The other specimen (in the Herbarium of the Florence Museum) 

 is on Bromus sterilis, and was collected in October. Here eio-ht 

 very young spores were seen in some of the asci. In the United 



